Method of making seamless tubes.



uw. OEFUTT. METHOD OF MAKING SEAMLESS 'l'UES Patented Oct. 8, 1912 l28HEETS-SHEET 1.

FIG.5

mvg-mon SEAMLESS TUBES,

APPLIUATION FILED SI1T.2B,1910.

0A w T E E H u... S T E E H qu 2 Patented Oct. 8,

s L 5 E. N w.. W

over a plug.

.ing operations.

VUNITED s Arias PATENT oFFIon.

JOHN W. OFFUTT, OF ELLWOOD CITY,\1ENNSYLVANIA, .ASSIGNOR TO THE SHELBYSTEEL TUBEV COMPANY, OF PITTSBURGH, .PIINNSYLTANIILI A CORPORATION OFNew .mn/snr. y

Specication of Letters Patent.

Patented oet. 8,1912.

Applicationled September 28, 1910. Serial `;t\To...54,339.

To all @ahem fit may concern Be it known that I, JOHN W. vOrrufrr, of`Ellwood City, .in the county of 'Lawrence and State of Pennsylvania,have invented a 5 new and useful Method of Making Seamless Tubes, ofwhich the following is -a full, clear, and exact description, referencebeing had to the accompanying drawings, .forming part of thisspecification. 5

My 'nvention relatcsto the 'manufacture of seamless tubes and moreparticularly relates to the manufacture ofhot finlshed tubes notnecessarily requiring furthercold' rolling or drawing operations' tocomplete 15 the tubes.

Heretoforc, in making sea-lnlesstubes, ,the billets after being piercedare lessened in diameter and wall-thickness in the passes of a rollingmill by reducing the pierced billets. In `the piercing operation and inreducing the billets by rolling over thel plugs, which are heldstationary 1n position in the passes formed between the rolls ofi therolling mill by means ofsuitfable.rodsI or` |25 mandrels, the surface ofthe pierced :billet or tube -is rough and irregular, thevinner sur--face of the hollow tube being scratched and roughened to such an extentthat the product is not salable until after furtherdinish- Owing to theconstruction of the reeling rolls employed in carrying out the reelingoperations, theA4 tube is rotated` about its longitudinal axis by thereeling operation. l'n the reclingmechanism shown,

3.5 While the reeling rolls and the frame in which the-reeling rolls aresupported rotate around the longitudinal axis of the tube, thefrictional resistance of the roll bearings and of the contactingsurfaces of the rolls and 40 the tub'e causes the tube and its mandrelto` rotate withthe -frame of the reeling mecha-1 l I,nism unless lmeans`are provided for holding.

and preventing such rotation of the tube and 'the .surface `defeat-te inthe rolled tubes are .not removed 1b `the action of the reeling.y

I rolls. :In additionito these defects,- the .tubes are notgformed trueto ga e or wall thickness, nor `are they of the l esired .round orcircular .cross section, a cold drawing op 'eratio ',.heing necessary toyfinish such .tubes .One object of my invention is to provide`anILilutifofoyed .method of making seamless 'tubes mj whichthe..pierccd tubes are aptomaltlcallydicld and;

l prevented from-rota ing ahoutftheirlougitudinal.axisv during the 'suctcessive forming operations, and surface detects removed fronrthctubesthereby.

Another object of the inventionis to provide an improved'method ofmaking seamless tubes in whichdefects upon the inner and outer surfacesof the tubesare eliminated and by which 'the'tubes are'completed to gageor wall Athickness and circular in cross section without cold drawing.

A further object-,of this invention is to provide an yimproved method ofmaking such .tubes by which tubes of the desired size and gageare'produced without grooves or scratches orother surface defectshereto- 'fore present in tubes as made by existing methods and a hotfinished seamless tube is made which is round or cylindrical and whichdoes not necessarily require further cold drawing operations i-n orderto be a marketable product.

A still `further object of my invention is to .provide ,a method ofmaking seamless tubes in which heated, pierced billets are placed upon amandrel and are then sub jected, in a series of continuous steps, torolling, reeling and sizing operations nrranged 'to `permit of the -easywithdrawal of the mandrel after `the sizing operations and to provide amethod of forming suchtubes permitting the use of a-mandrel shorter thanthe finished tube.

InIthe accompanying drawings, 'Figure 1 is a sectional plan showing fthepreferred ronstruction and `arrangementof apparatus for use in carryingout my improved method offorming-pierced billets into tubes. Fig. 2 is adiagrammatic `plan showing another arrangement of apparatus constructedand adapted for use 1n carrying out my improved method. Fig. 3 1sasectional side elevation of the rollingmill and the reeling rollsforming part of theapparatus shown in .Fig 2. Pig. 4 is a detaillongitudinal section showing, on `a larger scale, the reel. ino'mechanism of Figs. 1 and 2. .Fig. 5 `is a longitudinal plan, the billet-,being shown in longitudinal section, showingthe pierced billetor,partly Aformed tube in position on thermandrel as arranged during therolling and.rceling operations forming part of this..

furnace `in whiclhthe billets or blanks are heated, and B, 3, are theuolls of' a piercing mill .which is located conveniently 1n front -110"be heated to the desired temperature. The

' pierced or hole in the pierced billet A, as shown in.

, 10', 10g, of the continuous rolling mill l heated billets aresuccessively removed from the furnace and are subjected to a piercingoperation between the rolls` 3, 3.- ot` the piere- Iing mill,- the plug4 being held in position between the rolls `during the piercingoperation by the rod or mandrel 5. The billets are caused to travellengthwise during the piercing operation by rthe action of, the piercingrolls 3, 3, and finally are delivered upon the eonveyer (i. The rod ormandrel is then removed trom the pierced billet, the plug 4 having`become detached from the end of this rod or mandrel 5 at the comple`tion of the piercing operation, andA the billet, after the bar 5 isremoved, is delivered sidewise across the ways or skids 7 to theconveyer 8. A cylindrical mandrel 9, preferably oit greater length thanthe iinished tube is then'placed within the opening Fig. 5. The billet Aon its mandrel is then .fed forwardly between the `first`set of rolls 10of the rolling mill and passes between the rolls ot the successivestands of horizon ta'l and vertical rolls, 10, 10",' 10c, 10d, 10,

shown.

A. in which the tube is slightly In the iirst stand ot rolls 10 thebillet is forced tightly around the cylindrical mandrel 9 and isreduced. somewhat in cross sectional area, and, in the later stands ofrolls, the thickness of the wall and `cross sectional area of thepierced billet or partly finished tube A is further reduced and thetube. elongated. Ihevrollech partly formed tube, together with itsmandrel is then delivered forwardly' into the bite ot the reeling rolls11, reduced in wall thickness by the action. of the reeling rolls and ismade truly cylindrical giving the tube a yfinished surface. flhe tubewhich has been pressed tightly into very close contact upon the mandreli) by the action of v the-.rolls of the rolling mill, is increased inVbore and the mandrel is loosened by this reeling operation sutiicientlyto permit of its easy removal after the reeling'operation is completed.l

As shown in Fig. 2, the tube and its mani ,di-el are delivered from thereeling rolls 11 upon the conveyor 13 and are then transt'erred sidewiseupon the skids or ways llt to the conveyer 15. T he mandrel 9 is thenextracted from the rolled and recled tube,- power being applied whennecessary by means ot' the mechanism o the extractor bench 16, toe'l'ect'the removal of the Inandrel and the tube is delivered lengthwisebe` tweenl the rolls of the sizing apparatin formed as shown by thehorizontal rolls '12 and vertical rolls 12", and is formed to thedesired. diameten The siz'ed tubes are then delivered lengthwise by theconveyer 15 into the cross rolls 17 by which they' are straightened andcompleted, and the finished tubes are then delivered upon the conveyer18 leading from the cross rolls to a cooling bed orother place-ofdisposal.

1n using apparatus like that shown iu- Fig. ito carry out my improvedmethod, the pierced billets A after beingplaced on a mandrel, areintroduced into the rolls of the rolling mill as before described. Thewall thickness eda the tubeis reduced in the sue- .cessive passes`formed b these rolls and the tube is delivered there romnto ythereeling rolls. In this case the reeling rolls and the "frame onwhich therolls aremounted are constructed as shown in detail in Fig.4,anrl theframe and rolls are rotated about the longitudinal axis of the blank andmandrel 'in the saine mannen as shown .infFigs 9 and 3. The rolled andreeled blank upon emerging from the reeling'rolls entersthe sizingrolls. and a port-ion of the blank is sized while the mandrel is stillwithin the blank. The blank then passes to the mandrel extractor benchwhere the mandrel is removed Vfrom the sized tube.

`The reeling,r operation slightly increases the diameter of the openingor holevin thel tube and loosens the tube which has been tightly rolledupon the mandrel by the rolling operation. While the passes in thesizing rolls slightly reduce thediameter of the tubes, these passes areso proportioned that the tube, although reduced in diameter in beingsized, is not reduced sulliciently to be again closed tightly aiound themandrel within the tube. The sized tube, after the mandi-el is removed,then passes forwardly trom the sizing rolls to cross rolls, in which itis straightened in the saine manner as shown in Fig. 2 before described.The s'o finished tubes, after being cut to lengt-h, are in readiness forshipinentiinless itis desired to further reduce the tubes by a cold drawing process. Should suclncold drawing step be necessary, the hotfinished tubes are then pickled sind are cold drawn on drawing benches,'in the usual manner, which not forming part of my improved method neednot be lfurther describe( When a mandrel shorter than the finishedtubeis employed, instead of one which is .ot

greater length than'that of the finished tube, portions of the tube willhave a, lon itudinal movement `relative to the mandrel during therolling and reelingr operations.

The 'iuli'antages of my invention will be apparent to those skilledinthe art.

By using my improved method a hot iam;

4pierced eine@ 01 nwe is enigmi n a Single heels and in a,Y series ofcontinuons related steps Into u nislieclseeniless tube.

Modifications 1n' the cenetruetion end en l. rangement of the :q )pmatusfoi' carrying out .im wing i he apmy method muy be made with from myYinvention Aas defim` 'ended claims. -l`While preferehlT 'ie11`,bbviouslypierced billets may be healed the heet-K l .1l-:Ll: blanks are pier'cedund hen @rushed et. eleiinitlel heet, prier to the piercing @perve-Lemme the steps eonsisting in subjecting a heated tubular blank while on4:i mandrel succesi sively and simultaneously-to the action'of thesollsof rolling mill, a reeling machine and ef sizing rolls to thereby formthe tubes in a, manner a'ordng e continuous'opera.- tion.

3. 1n thennannfeture ofseizinless ltubes,

the steps consisting in subjecting eheated tubular blank ywhile on amandrel successively to the action o the rolls of a'ji-olling mill, ereeling machine and of sizingblls,

lhe aelzion of the reeling and of fthe .Sizing rollsV being simultaneousto-thereby form the ,tubes 1n a" manner aerdmg a continuous operation.

.ln testimony whereof, I have hereunto set my hand.

l JQHNWUEFUW *Witnesses/I l Y flBRowN, Y

Leggere H. llllfmn.

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